Elie Metchnikoff, a Nobel Prize-winning scientist known for his groundbreaking work on the immune system, delves into humanity's obsession with aging. He believed aging was a disease and conducted fascinating research, including interviews with centenarians and exploring the health benefits of yogurt. The discussion touches on his meeting with Leo Tolstoy, contrasting views on aging, and the societal implications of extending life. Metchnikoff's relentless curiosity led him to advocate for longevity and challenge perceptions of aging, sparking a yogurt revolution that changed dietary habits.